Self-engaging, automatically-releasing sash balance locking device



Apnl 16, 1968 w. H. BLOOM 3,377,648

SELF-ENGAGING, AUTOMATICALLY-RELEASING SASH BALANCE LOCKING DEVICE Filed March 1, 1966 FIG. 1

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AT TO RN EYE WILLARD H. BLOOM United States Patent 3,377,648 SELF-ENGAGING, AUTOMATICALLY-RELEASING SASI-I BALANCE LOCKING DEVECE Willard H. Bloom, Oak Harbor, Ohio, assignor to Formetal, Inc., Oak Harbor, Uhio, a corporation of Ohio Filed Mar. 1, 1966. Ser. No. 530,957 Claims. (Cl. 16-197) ABSTRACT 8F THE DISCLOSURE This self-engaging automatically-releasing sash balance locking device for a resilient sash balancing member anchored to and housed within a longitudinally-slotted casin g adapted to be secured to the window frame of a removable sliding sash window installation contains but a single relatively moving locking part. The latter is directly connected to the sash balancing spring, thereby giving instant response as well as simplicity of construction. This looking device has a two-part slide block containing the locking part, thereby facilitating assembly operations during manufacture. The locking part consists of a hook-shaped locking lever with an L-shaped forward lock-operating arm, a U-shaped bend at the pivot location and an upwardly-directed rearward locking arm with a sharp-edged upper end portion which provides the locking effect by indenting the sash balance casing when the outer end of the forward arm of the lever is released by the withdrawal of the sash.

FIGURE 1 is a fragmentary vertical section through a window frame with a channel sash guide and through the adjacent portion of a removable sash with the slide block side plate removed, showing the self-locking automaticah ly-releasing sash balance locking device of one form of the invention;

FIGURE 2 is a side elevation of the sash balance lock of FIGURE 1, with the slide block side plate attached;

FIGURE 3 is a left-hand or front elevation of F1"- URE 2;

FIGURE 4 is a right-hand or rear elevation of FIG- URE 2, with the sash balancing spring omitted; and

FIGURE 5 is a top plan view of FIGURE 4.

Referring to the drawing in detail, FIGURE 1 shows, in a vertical section plane parallel to the window pane, a removable double-hung sash window installation, generally designated 10, including a window frame 12 equipped with a channel sash guide 14 and a sliding window sash 16 containing a sash balance lock tripper 18 for a self-locking automatically-releasing sash balance, genr erally designated 20, including a balancing spring 22 and a locking device 24 connected thereto. The window frame 12, channel sash guide 14, sash 16 and tripper 18 are conventional and their details are beyond the scope of the present invention. The sash balance 26 and the tripper 18 are adapted to be installed in either the lower or the upper sash of the double-hung sash installation and may also be installed on only one side or on opposite sides of the sashes 16; in either case one of the channel sash guides 14 is yieldably mounted on springs, as is conventional in the building construction industry and is shown, for example, in the Haas Patents 2,747,219 of May 29, 1956 and 2,791,795 of May 14, 1957, each for Self-Locking Sash Balance. Accordingly, the details of such installations as shown in these exemplary patents are omitted as being unnecessary to the present disclosure because well-known to those skilled in the window art.

The tripper 13 is also disclosed and claimed in the Haas Patent 2,796,630 of June 25, 1957, for Self-Locking Sash Balance. In brief, it consists of a cup-shaped housing 26 of square cross-section seated in and secured to a socket 2-8 in the sash 16 and indented to form a stop projection 30 which extends downward into a slot 32in the top of a hollow plunger 3-4 of square cross-section reciprocably mounted in the housing 26 and having a nose portion 36 which has a beveled or inclined upper face and a horizontal face 40. The plunger 34 is yieldingly urged outward from its housing 26 by a helical compression spring 42, as limited by the projection 3-1} against the rearward end of the slot 32.

The sash guide channel 14 mounted in the window frame 12 is ordinarily of metal, either rolled or extruded into its channel shape and containing a casing portion 44 including a rear wall 46 and a slotted front wall 48 interconnected by op-posite parallel side walls 49, the front wall 48 having an elongated vertical central slot 50. The sash guide channel 14, of which there are four in the usual double-hung window sash installation 10, is ordinarily made of metal such as aluminum. If made of other material, such as synthetic plastic material, an elongated metal strip liner 52 is preferably provided and riveted or otherwise secured to the rear wall 46 inside the elongated chamber 54 containing the self-locking sash balance 20. As shown in the previously-cited Haas patents, the sash balancing spring 22 is a tension spring of elongated form with its looped upper end (not shown) anchored to the upper end of the channel sash guide 14. The looped lower end 56 of the sash balancing spring 22 engages the L- shaped forward operating arm or trigger arm 58 of a hook-shaped pivotally-oifset locking lever 60. The L shaped forward or operating arm 58 of the locking lever 60 has an approximately horizontal upper part 62 and an approximately vertical lower part 64 joining one another at a corner or junction 66. The lower end of the vertical part 64 terminates at a reversely-bent approximately U-shaped arcuate pivotal portion 68 from which a rearward locltin g lever arm 70- extends upward approximately parallel to the lower part 64 of the forward arm 58 and terminates at its upper end in a. sharp locking edge 72. The latter is adapted to engage and slightly indent the liner 52, if used, or the channel guide rear wall 44, in its absence.

The locking lever '60 is pivotally mounted within a runner or lock carrier 74 in the form of a hollow block 76 with an open side which is closed by a cover or side plate 78. For this purpose, the block '76 at its open side is provided with laterally-extending integral peg-like protuberances 80 which are snugly secured in correspondingly-located holes 82 in the side plate 78. The block 76 is provided with vertically-spaced upper and lower front walls 84 and 36 respectively and vertically-spaced upper and lower rear walls 83 and respectively. The trigger portion 58 of the locking lever 66 extends forwardly through the gap or opening 92 between the upper and lower front walls 34 and 86, whereas the upper rear wall 88 terminates in a rounded fulcrum portion 94 above a gap 96 between it and the lower rear wall 90, the fulcrum portion 94 being shaped to fit the bend or pivotal portion 68 which rocks pivotally thereagainst so as to move the sharp edge 72 of the rearward arm 70 into and out of locking engagement with the casing rear wall liner 52. The lower loop 56 of the balancing spring 22 encircles the locking lever 60 adjacent the junction 62 of the horizontal forward or trigger portion 58 and the vertical arm 66 of the U-shaped portion 64. From FIGURE 5 it will be observed that the forward arm or trigger portion 58 of the locking lever 60 is considerably narrower than the locking arm portion 70 and passes through a slot or opening 98 in the upper front wall portion 48 (FIG- URE 3).

In the operation of the invention, let it be assumed that the locking device 64} has been mounted within the casing portion 54 of the channel sash guide 14, and the lower loop 56 of the sash balancing spring 22 hooked over the forward or operating arm 58 of the locking lever 60 adjacent the corner 66, as shown in FIGURE 1. Let it further be assumed that a window sash 16 is in position vertically slidably mounted in the sash guide 14 and in the opposite sash guide (not shown), with the plunger 34 coming to rest above the trigger portion 53 of the locking lever 60. The weight of the sash 16 applied to the upper or trigger portion 62 of the operating arm 58 by the bottom surface 40 of the plunger 34 pushes the trigger portion 58 downward from the dotted line position of FIGURE 1 to the solid line position thereof. This action swings the locking lever 60 around the fulcrum 94-, thereby swinging its rearward arm 70 and the locking edge 72 thereon out of locking engagement with the liner strip 52 on the rear wall 46 of the casing 44 and freeing the sash balancing spring 22 to assume its function of counter-balancing the weight of the sash 16.

If, now, the operator removes the sash 16 in the usual manner by pushing it to the left in FIGURE 1 to correspondingly push to the left the resiliently-mounted opposing channel sash guide (not shown), and then swings forward the right-hand edge portion of the sash 16, thus freed from the sash guide 14, he thereby disengages the nose portion 36 of the plunger 34 from the trigger portion of upper part 62 of the operating arm 58 of the locking lever 60. In response to the upward pull of the sash balancing spring 22, the locking lever 64 rocks clockwise around the fulcrum 94, causing the forward or operating arm 53 to be pulled upward by the balancing spring loop 56 into the dotted line position of FIGURE 1 and the rearward arm '70 to swing rearwardly into the similar dotted line position, engaging the locking edge 72 with the liner strip 52 of the back wall 46 of the channel sash guide 14 and locking the sash balance 20 in its attained position.

When the operator reinserts the sash 16 by reversing the above-described procedure, let it be assumed that he does so with the nose portion 36 of the plunger 34 disposed above the upper part 62 of the operating arm 58 of the locking lever 69 so that when the sash 16 is pulled downward, the nose portion 56 swings the locking lever 60 from the dotted line to the solid line position of FIGURE 1. This action swings the pivotal portion 68 and rearward arm 70 of the locking lever 60 counterclockwise around the fulcrum 94-, disengaging the locking edge 72 from the liner strip 52 and releasing the sash balancing spring 22 to reassume its balancing function.

On the other hand, if the operator inserts the sash 16 with the nose portion 36 of the plunger 34 in the dotted line position of FIGURE 1 below the upper part or trigger part 62 of the locking lever forward arm 58, when he raises the sash 16 and with it the tripping device 18, he thereby causes the inclined upper face 38 to engage the forward end of the upper part 62, which thereby pushes the plunger 3 to the left by a carnming action against the thrust of the compression spring 42. When the nose portion 36 of the plunger 34 passes the end of the operating arm 58, the spring 42 immediately urges the plunger 34 to the right above the operating arm 58 which is now in its dotted line locking position of FIGURE 1. When the operator now pulls downward upon the sash 16, the horizontal lower face 40 of the plunger nose Portion 36- engages and pushes downward the forward or operating 4 arm 58, swinging the lever arm 60 counterclockwise around the fulcrum portion 94 and disengaging the locking edge 72 from the liner strip 52. When this occurs, the balancing spring 22, thus unlocked, resumes its balancing function.

What I claim is:

1. A self-engaging automatically-releasing sash balance locking device for a resilient sash balancing member anchored to and housed within a longitudinally-slotted casing adapted to be secured to the window frame of a removable sliding sash window installation, said locking device comprising a lock carrier adapted to be slidably mounted in the casing and having a fulcrum thereon,

and a hook-shaped pivotally-olfset sash balancing member locking lever having an approximately U-shaped pivotal portion pivotally engaging said fulcrum, said locking lever including a bent forward lever arm adapted to be connected intermediate its opposite ends to the sash balancing member and extending upward and forward from said pivotal portion through the casing slot and adapted to extend into the path of travel of the sash, and a rearward locking lever arm extending upward and rearward from said pivotal portion and having a sharp-edged upper end movable into locking engagement with the casing in response to tile upward pul of the resilient sash balancirg member on said forward lever arrn during (lac absence of the sash from the window frame.

2. A rtelf-engagir ":1tomatically-releasing sash balance locking device, according to claim 1, wherein said forward lever arm is approximately L-shaped,

3. A self-engaging automatically-releasing sash balance locking device, according to claim 2, wherein said L- shaped lever arm has an approximately horizontal upper forward part and an approximately vertical lower rearward part, and wherein the resilient sash balancing member is adapted to he connected to said L-shaped lever arm adjacent the junction of said upper and lower parts.

4. A self-engaging automatically-releasing sash balance locking device, according to claim 1, wherein said lock carrier comprises a hollow block and wherein said fulcrum consists of a transversely-disposed portion within said block and integral therewith.

5. A self-engaging automatically-releasing sash balance locking device, according to claim 4, wherein said block has a main portion open at one side and including said fulcrum and also has a cover portion secured to said main portion in closing relationship with the open side thereof.

References Cited UNITED STATES PATENTS 3,078,523 2/1963 Martin 16197 3,124,849 3/1964 Osten 16197 MARVIN A. CHAMPION, Primary Examiner.

J. H. MCGLYNN, Assistant Examiner. 

